Visual Computing Seminar Schedule
Spring Semester, 2011

ABSTRACTS OF TALKS

Jan. 21 Brian Malloy, An Approach to Dynamic Object Visualization in C++ Programs

This talk presents an approach to modeling and visualizing the dynamic interactions among objects in a C++ application. We exploit UML diagrams to expressively visualize both the static and dynamic properties of the application. We make use of a class diagram and call graph of the application to select the parts of the application to be modeled, thereby reducing the number of objects and methods under consideration with a concomitant reduction in the cognitive burden on the user of our system. We use aspects to insert probes into the application to enable profiling of the interactions of objects and methods and we visualize these interactions by providing sequence and communication diagrams for the parts of the program under study. We complement our static selectors with dynamic selectors that enable the user to further filter objects and methods from the sequence and communication diagrams, further enhancing the cognitive economy of our system. A key feature of our approach is the provision  for dynamic interaction with both the profiler and the application. Interaction with the profiler enables filtering of methods and objects. Interaction with the application enables the user to supply input to the application to provide direction and enhance comprehension or debugging.

Bio: Brian Malloy is an Associate Professor in Clemson University's School of Computing. His research interests are in software analysis, comprehension, visualization, testing, and maintenance, as well as compiler technology, grammarware, front-end construction and development. In addition he is well known at Clemson for his teaching of 2D and 3D Video Game Development. His Ph.D. in Computer Science is from the University of Pittsburgh. He also holds M.S. and M.Ed. degrees from Pittsburgh, and a B.A in Mathematics from LaSalle.

Feb. 4 — Donald House, Mesh Colors

Abstract: This seminar reports on a 2010 TOG paper by Cem Yuksel, John Keyser and Donald House. The coloring of three dimensional models using two or three dimensional texture mapping has well known intrinsic problems, such as mapping discontinuities and limitations to model editing after coloring. Workarounds for these problems often require adopting very complex approaches. Here we propose a new technique, called mesh colors, for associating color data directly with a polygonal mesh. The approach eliminates problems deriving from using a map from texture space to model space. Mesh colors is an extension of vertex colors where, in addition to keeping color values on each vertex, they are also kept on edges and faces. Like texture mapping, the approach allows higher texture resolution than model resolution, but at the same time it guarantees one-to-one correspondence between the model surface and the color data, and eliminates discontinuities. We show that mesh colors integrate well with the current graphics pipeline and can be used to generate very high quality textures.

Bio: Donald House is Professor and Chair of Visual Computing in Clemson University's School of Computing. His specialites are in the broad areas of computer graphics and visualization with focus on physical simulation applied to animation, and on perceptual issues in visualization. He received his B.S. in Mathematics from Union College, his M.S. in Electrical Engineering from Rensselaer, and his Ph.D. in Computer Science from the University of Massachusetts/Amherst.

Feb. 11 Casey Johnson, Tony Liu, and Nick Kinerd, Production Focus on the Making of Spider Fight

Abstract: This talk will cover the production pipeline as it pertains to the making of the short film, "Spider Fight."  Three members of the team behind the project will discuss it's development starting from the initial story idea and concept art through to the animation and rendering of the short.  Emphasis will be given to the topics of character development, rigging, animation, and rendering.

Bios: Casey Johnson graduated from Middle Tennessee State University in 2000.  He worked professionally in the fields of corporate video, graphic design, and 3d before starting his MFA at Clemson in the fall of 2009.  He is currently a DPA student with a projected graduation date of August, 2011. Tony Liu is a Computer Science graduate of Clemson who started the DPA program in 2009, hoping to use his Computer Science background with his art interests. Nick Kinerd graduated with a B.S. in Graphic Communications from Clemson University in 2007. With a special interest in motion capture, animation and video games, he entered the MFA program at Clemson in the fall of 2009

Feb. 25 Ryan Prestridge, Matias Volonte, Production Focus on the Making of LiFe

Abstract: LiFe is an animated short film currently under production in the Digital Production Arts program, that features cave dwelling creatures that feed on light. The animation is about discovering that there is more to life than the routine. Ryan and Matias will discuss the different methods being used to create the film, and will reveal the production process that they are following.


Bios: Ryan Prestridge graduated from Appalachian State University with a BFA in sculpture. Matias Volonte holds a BS in Audiovisual Communication from the Universidad Blas Pascal, in Cordoba, Argentina. Both Ryan and Matias are second year students in the Digital Production Arts MFA progr
am.

March 4 Robert Geist, TEXNH Trees: A New Course in Data Structures


Abstract: The TEXNH method is an approach to undergraduate computer science education that is based on cognitive constructivisim, in the sense of Piaget, and which invokes several course design directives that include re-combining art and science, problem-based learning, problem selection from the visual problem domain, and cognitive apprenticeship. The paper describes a new texnh course in data structures. It includes a full comparative assessment of the realized improvement in student problem solving capability and, for the first time, cognitive authenticity in problem selection, in that the course problem is a variation on a very recent research result.


Bio: Robert Geist is a Professor in the Visual Computing division of the School of Computing at Clemson. He received a B.A. in mathematics and an M.A. in computer science from Duke University and an M.S. in mathematics and a Ph.D. in mathematics from the University of Notre Dame. He was an Assistant Professor and Associate Professor of mathematics at the University of North Carolina at Pembroke and an Assistant Professor and Associate Professor of computer science at Duke University before joining the faculty at Clemson. His current research is in computer graphics and includes applications of cellular automata to modeling and rendering natural phenomena and techniques for color gamut reduction in both image fusion and image enhancement for color-deficient observers.



March 11 Brandon Pelfrey, Adaptive Neighbor Pairing for Smoothed Particle Hydrodynamics, with Donald House


Abstract: Smoothed Particle Hydrodynamics (SPH) is a method for fluid simulation by using particles to represent discrete bits of volume. In calculating forces, SPH requires each particle to find all other particles within a neighborhood. Since this takes place each time step, it tends to dominate the computation. We speed up this process by reusing lists of particles over time steps. Using simple rules that tell us when a particle must recalculate its neighborhood, we are able to make an appreciable speed up in performance. Results are shown for some simple 2D and 3D cases.


Bio: Brandon Pelfry is an M.S. student in Computer Science and Clemson. He completed his B.A. in Computer Science with a Minor in Mathematics at Clemson in 2010. He is currently pursing research computer graphics.


April 1 Christopher Corsi, Methods for Computing Tire/Track Intersections, with Robert Geist, and James Mike Westall

Abstract:
A problem that arises naturally in the real-time simulation of race car motion is the calculation of tire/track intersection points, given track geometry, a wheel hub position, and a wheel plane normal. The challenge arises from handling very large track models, which may comprise millions of polygons, and still meeting tight timing constraints, which require more than 5,000 lookups/second. Three methods of solution are proposed, and the performance and reliability of each is discussed.

Bio: Christopher Corsi is a 2nd year undergraduate computer science major in Clemson University's School of Computing.

April 8 James Mike Westall, High Performance Extraction of Telemetry Data from Online Video, with Robert Geist, Christopher Corsi, Dennis Lingerfeld

Abstract:
Consider a computer application such as a flight simulator that might be used in pilot training. The simulator displays digital and analog telemetry data that is continually updated. Detailed analysis of this data can be be useful in evaluating the performance of the trainee and comparing the trainee's performance to that of an experienced pilot flying the same exercise. A potential obstacle is that the simulator might not support digital recording of the telemetry required for the analysis. In that case, the task can be accomplished in a twostep process. First, any one of a number of screen capture tools can be used to create a video of the telemetry window at a specified frame rate. Then, the recorded video is processed one frame at a time by a program that analyzes the pixel data and performs automated character and analog instrument recognition. We will describe a system of this general class and its realworld application. In the target application, videos are recorded at 10 frames per second and have a duration of approximately three hours. Each frame of compressed video contains 14 numeric fields and 2 analog gauges. Our system, which is presently purely serial and unoptimized, can process the 108,000 frames of a three hour video in 170 seconds of real time. This corresponds to a rate of 635 frames per second being read in, decompressed, converted from YUV to RGB and processed. Approximately 60% of the elapsed time is consumed in the processing phase. Approximately 4 million numerals are located, segmented, and recognized in the course of processing the full video

Bio: James M. Westall received the M.S. degree in Computer Science and the Ph.D. degree in Mathematics from the University of North Carolina at Chapel Hill. He is a Professor of Computer Science in the School of Computing at Clemson University. His current research interests include measurement and modeling of  computer systems and networks, computer graphics,  and high-performance computing. In a previous life (1986-1997), he spent eleven years as a consultant to the IBM
facility in Charlotte, NC. In this role, he was responsible for the development of a major component of  commercial system for automated recognition of handwritten numerals on bank checks.



Yolanda Rankin, IBM Research - Almaden, More than Just a Game: Critical In-Game Interactions that Facilitate Second Language Acquisition

Abstract: Unlike recreational games, serious games do more than entertain the player. Serious games promote acquisition of information and skills that are valued in both the virtual world and the real world. Designing a serious game requires a considerable amount of resources, including time, money, and a talented development team. Even with these efforts, it is possible to design a serious game that lacks the element of fun. Rather than designing a serious game from scratch, we re-purpose the commercial Massively Multiplayer Online Role Playing Game (MMORPG) EverQuest® II as a serious game, leveraging the entertainment value and readily available development tools to promote learning in the context of Second Language Acquisition (SLA). First, we identify the affordances attributed to MMORPGs and evaluate the impact of gameplay experiences on students’ SLA. Promising results from experimental studies reveal that in-game social interactions in the target language between native speakers and non native speakers increase second language vocabulary acquisition and reading comprehension skills compared to traditional classroom instruction. Finally, we develop ClockWerk©, a temporal visualization tool that graphically depicts dominant communication patterns of linguistically diverse groups of players during gameplay, enabling us to gauge their impact on SLA.

Bio:  Yolanda A. Rankin, Ph.D., is Research Scientist at IBM Research Almaden in San Jose, CA. Her research utilizes social interactions as the motivation for design guidelines for user interfaces in a variety of contexts, including video games for second language acquisition, virtual environments as an alternative self service platform for customer support, and methodology and supporting tools to assist service delivery organizations with understanding and evaluating the customer experience as a method for improving service quality. Yolanda has accumulated more than eight years experience in industry as a software engineer at Lucent Technologies-Bell Labs and as a senior program manager at Luxcore Networks. She has received numerous honors and awards, including the National Science Foundation Graduate Research Fellowship, Northwestern University Graduate School Fellowship, Alliance of Graduate Education and the Professoriate (AGEP) Scholarship among others. Yolanda completed her Ph.D. in Computer Science at Northwestern University, a M.A. in Computer Science at Kent State University and her B.S. in Mathematics at Tougaloo College.

Cem Yuksel, Cornell University, Developing Efficient Graphics Technologies for Physically-based Modeling

Abstract: As we try to build virtual representations for more and more complicated environments in graphics, computational efficiency often becomes the determining factor in how useful a particular graphics technique is in practice. In this talk I will present my approach for developing efficient graphics technologies, which consists of three steps: visual analysis of the subject physical phenomenon, understanding of the physical models that describe the phenomenon, and devising algorithms that fit well to the target computer hardware. The visual analysis helps separate the phenomenon into its visual components and identify which one of these components have deterministic behavior, while understanding the physical models makes it possible to propose simpler models that properly approximate the important visual components. Finally, efficient algorithms can be developed for simplified physical models considering the architectural strengths of the desired computer hardware. I will explain how this approach helped in developing efficient technologies by presenting two separate research topics as examples: water simulation and realistic hair rendering. For water simulation I will talk about the wave particles method for real-time simulation of water surface waves. The wave particles method can achieve about 6 orders of magnitude speed up as compared to the most efficient full fluid simulations in graphics. As a result, scenes with very high complexity can be simulated with high frame rates. As for hair rendering, I will present the dual scattering method for approximating multiple scattering of light in human hair. Multiple scattering plays a crucial role in defining the perceived color of hair and a physically based computation of multiple scattering is important for generating realistic hair images. While previous methods required hours to compute multiple scattering for a single hair image, the dual scattering method can properly approximate the same computation at real-time frame rates with high visual accuracy.

Bio: Cem Yuksel is a postdoctoral fellow at Cornell University and the founder of Cyber Radiance LLC. He received his PhD in Computer Science from Texas A&M University in 2010. His research covers a wide range of topics in computer graphics, starting from physically based simulation to realistic image synthesis. His research on real-time water simulation, hair rendering, and texture mapping has received strong interest from many companies in the graphics industry. Furthermore, he designed and programmed Hair Farm, a leading hair software plugin for 3ds Max, used by many production studios and individual artists. He has a BS in Physics and MS in Computer Engineering from Bogazici University in Turkey. He also studied in the Visualization Program at Texas A&M University, and Visual Arts and Communication Design at Sabanci University in Turkey.